Here is the full list of all 45 Blasphemous achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Achieve the maximum value of fervor.
Achieve the maximum value of health.
Achieve the maximum value of flasks.
Get all rosary beads.
Achieve the maximum value of rosary bead slots.
Unlock the ending A.
Beat His Holiness Escribar.
Bring all the offerings to the Blessed Lord of Salty Shores.
Get all relics.
Help the Pilgrim reach his final destination.
Achieve the maximum level of the Mea Culpa sword.
Discover all zones.
Beat Crisanta of the Anointed Blade.
Buy all the items of the Candelaria shops.
Beat all the arena challenges.
Beat Exposito, Scion of Abjuration.
Beat Quirce, Returned by the Flames.
Beat all types of enemies.
Beat Melquíades, The Exhumed Archbishop.
Hatch the Egg of Altasgracias.
Witness the last moments of Viridiana.
Beat the Tres Angustias.
Execute 5 different enemies.
Beat the Our Lady of the Charred Visage.
Kill 666 enemies.
Beat Perpetua.
Beat Ten Piedad.
Use the Righteous Riposte 5 times.
Beat the Warden of the Silent Sorrow.
Beat Esdras, of the Anointed Legion.
Unlock the ending B.
Release all cherubs.
Talk with all the corpses.
Get all prayers.
Get all collectibles.
Get all sword hearts.
Visit the tomb of The Lady of the Tailed Gown.
Bring all the offerings to Lvdovico.
Help Cleofás in his path of redemption.
Save all Kissers of Wounds.
Buy all skills from the Mea Culpa shrines.
Provoke the meeting between Redento and Cleofás.
Beat all bosses without flask consumption.
Cross the Bridge door in less than 3 hours.
Get 100% of the game.